#!/usr/bin/env bash
set -euo pipefail
# Disable history expansion so PUBLISH_URL values with "!" are safe when sourcing env files.
set +H

ENV_FILE="${VIDEO_ENV_FILE:-/var/lib/roverd/video.env}"

if [[ ! -f "$ENV_FILE" ]]; then
	echo "Environment file ${ENV_FILE} missing; cannot publish" >&2
	exit 1
fi

# shellcheck disable=SC1090
# Strip any CRLFs to avoid sourcing a PUBLISH_URL with a stray carriage return in the name.
source <(tr -d '\r' < "$ENV_FILE")
PUBLISH_URL="${PUBLISH_URL:-}"
if [[ -z "${PUBLISH_URL}" ]]; then
	# Fallback parser in case sourcing missed due to weird whitespace/BOM
	PUBLISH_URL="$(grep -E '^PUBLISH_URL=' "$ENV_FILE" | head -n1 | cut -d= -f2- | tr -d '\r')"
fi
if [[ -z "${PUBLISH_URL}" ]]; then
	echo "PUBLISH_URL not set in ${ENV_FILE}; contents:" >&2
	sed -n '1,200p' "$ENV_FILE" >&2
	exit 1
fi

VIDEO_WIDTH="${VIDEO_WIDTH:-1920}"
VIDEO_HEIGHT="${VIDEO_HEIGHT:-1080}"
VIDEO_FPS="${VIDEO_FPS:-30}"
VIDEO_BITRATE="${VIDEO_BITRATE:-3000000}"
AUDIO_ENABLE="${AUDIO_ENABLE:-0}"
AUDIO_DEVICE="${AUDIO_DEVICE:-hw:0,0}"
AUDIO_CODEC="${AUDIO_CODEC:-pcm_s32le}"
# Keep the audio path simple for the Pi Zero; default to raw PCM (no encoding) and honor overrides.
AUDIO_RATE="${AUDIO_RATE:-48000}"
AUDIO_CHANNELS="${AUDIO_CHANNELS:-1}"
# AUDIO_FORMAT is the ALSA format; FFmpeg expects lowercase.
AUDIO_FORMAT="${AUDIO_FORMAT:-S32_LE}"
AUDIO_FORMAT_FFMPEG="$(printf '%s' "${AUDIO_FORMAT}" | tr 'A-Z' 'a-z')"
# Flip the camera 180deg (supported by rpicam-vid/libcamera-vid)
FLIP_ARGS=(--rotation 180)

if [[ -n "${LIBCAMERA_BIN:-}" ]]; then
	LIBCAMERA_BIN_PATH="$LIBCAMERA_BIN"
elif command -v rpicam-vid >/dev/null 2>&1; then
	LIBCAMERA_BIN_PATH="$(command -v rpicam-vid)"
elif command -v libcamera-vid >/dev/null 2>&1; then
	LIBCAMERA_BIN_PATH="$(command -v libcamera-vid)"
else
	echo "Neither rpicam-vid nor libcamera-vid found; install libcamera-apps." >&2
	exit 1
fi

if [[ -n "${FFMPEG_BIN:-}" ]]; then
	FFMPEG_BIN_PATH="$FFMPEG_BIN"
elif command -v ffmpeg >/dev/null 2>&1; then
	FFMPEG_BIN_PATH="$(command -v ffmpeg)"
else
	echo "ffmpeg not found; install it via apt install ffmpeg." >&2
	exit 1
fi

run_pipeline() {
	if [[ "${AUDIO_ENABLE}" -eq 1 ]]; then
		# Capture audio with arecord into a FIFO so ffmpeg just muxes it.
		AUDIO_FIFO="$(mktemp -u /tmp/roverd-audio.XXXXXX)"
		rm -f "${AUDIO_FIFO}"
		mkfifo "${AUDIO_FIFO}"
		ACTIVE_AUDIO_DEVICE="${AUDIO_DEVICE}"
		ACTIVE_AUDIO_FORMAT="${AUDIO_FORMAT}"
		ACTIVE_AUDIO_CODEC="${AUDIO_CODEC}"
		# Background ALSA capture; keep it simple to avoid CPU on ffmpeg.
		if ! arecord -D "${ACTIVE_AUDIO_DEVICE}" -f "${ACTIVE_AUDIO_FORMAT}" -r "${AUDIO_RATE}" -c "${AUDIO_CHANNELS}" -q -t raw "${AUDIO_FIFO}" &
		then
			echo "Audio capture failed (arecord, ${ACTIVE_AUDIO_DEVICE} ${ACTIVE_AUDIO_FORMAT}); trying fallback to plughw S16_LE" >&2
			ACTIVE_AUDIO_DEVICE="plughw:0,0"
			ACTIVE_AUDIO_FORMAT="S16_LE"
			ACTIVE_AUDIO_CODEC="pcm_s16le"
			if ! arecord -D "${ACTIVE_AUDIO_DEVICE}" -f "${ACTIVE_AUDIO_FORMAT}" -r "${AUDIO_RATE}" -c "${AUDIO_CHANNELS}" -q -t raw "${AUDIO_FIFO}" &
			then
				echo "Audio capture failed (fallback); falling back to video-only" >&2
				AUDIO_ENABLE=0
				rm -f "${AUDIO_FIFO}"
			else
				ARECORD_PID=$!
				trap 'kill "${ARECORD_PID}" >/dev/null 2>&1 || true; wait "${ARECORD_PID}" 2>/dev/null || true; rm -f "${AUDIO_FIFO}"' EXIT INT TERM
			fi
		else
			ARECORD_PID=$!
			trap 'kill "${ARECORD_PID}" >/dev/null 2>&1 || true; wait "${ARECORD_PID}" 2>/dev/null || true; rm -f "${AUDIO_FIFO}"' EXIT INT TERM
		fi
		ACTIVE_AUDIO_FORMAT_FFMPEG="$(printf '%s' "${ACTIVE_AUDIO_FORMAT}" | tr 'A-Z' 'a-z')"

		# Try audio + video; if audio device is missing, fallback to video-only.
		if [[ "${AUDIO_ENABLE}" -eq 1 ]] && ! "${LIBCAMERA_BIN_PATH}" \
			--inline \
			--timeout 0 \
			--width "${VIDEO_WIDTH}" \
			--height "${VIDEO_HEIGHT}" \
			"${FLIP_ARGS[@]}" \
			--framerate "${VIDEO_FPS}" \
			--bitrate "${VIDEO_BITRATE}" \
			--codec h264 \
			--profile baseline \
			--denoise cdn_off \
			--nopreview \
			--awb custom \
			--awbgains 1.5,1.8 \
			--output - \
			| "${FFMPEG_BIN_PATH}" \
				-hide_banner \
				-loglevel warning \
				-fflags nobuffer \
				-use_wallclock_as_timestamps 1 \
				-thread_queue_size 512 \
				-f h264 \
				-i pipe:0 \
				-f "${ACTIVE_AUDIO_FORMAT_FFMPEG}" \
				-ar "${AUDIO_RATE}" \
				-ac "${AUDIO_CHANNELS}" \
				-i "${AUDIO_FIFO}" \
				-c:v copy \
				-c:a "${ACTIVE_AUDIO_CODEC}" \
				-ar:a "${AUDIO_RATE}" \
				-ac:a "${AUDIO_CHANNELS}" \
				-flush_packets 1 \
				-f mpegts \
				"${PUBLISH_URL}"
		then
			echo "Audio pipeline failed; falling back to video-only this run" >&2
			AUDIO_ENABLE=0
		fi
		if [[ -n "${ARECORD_PID:-}" ]]; then
			kill "${ARECORD_PID}" >/dev/null 2>&1 || true
			wait "${ARECORD_PID}" 2>/dev/null || true
			rm -f "${AUDIO_FIFO}"
			trap - EXIT INT TERM
			unset ARECORD_PID
		fi
	fi

	if [[ "${AUDIO_ENABLE}" -ne 1 ]]; then
		"${LIBCAMERA_BIN_PATH}" \
			--inline \
			--timeout 0 \
			--width "${VIDEO_WIDTH}" \
			--height "${VIDEO_HEIGHT}" \
			"${FLIP_ARGS[@]}" \
			--framerate "${VIDEO_FPS}" \
			--bitrate "${VIDEO_BITRATE}" \
			--codec h264 \
			--profile baseline \
			--denoise cdn_off \
			--nopreview \
			--awb custom \
			--awbgains 1.5,1.8 \
			--output - \
			| "${FFMPEG_BIN_PATH}" \
				-hide_banner \
				-loglevel warning \
				-fflags nobuffer \
				-use_wallclock_as_timestamps 1 \
				-thread_queue_size 512 \
				-f h264 \
				-i pipe:0 \
				-c:v copy \
				-an \
				-flush_packets 1 \
				-f mpegts \
				"${PUBLISH_URL}"
	fi
}

while true; do
	if run_pipeline; then
		exit 0
	fi
	echo "Video publisher exited, restarting in 2s..." >&2
	sleep 2
done